Defining the Surface Oxygen Threshold That Switches the Interaction Mode of Graphene Oxide with Bacteria

Guo, Zhiling, Zhang, Peng, Xie, Changjian, Voyiatzis, Evangelos, Faserl, Klaus, Chetwynd, Andrew J ORCID: 0000-0001-6648-6881, Monikh, Fazel Abdolahpur, Melagraki, Georgia, Zhang, Zhiyong, Peijnenburg, Willie JGM
et al (show 3 more authors) (2023) Defining the Surface Oxygen Threshold That Switches the Interaction Mode of Graphene Oxide with Bacteria. ACS NANO, 17 (7). pp. 6350-6361.

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As antimicrobials, graphene materials (GMs) may have advantages over traditional antibiotics due to their physical mechanisms of action which ensure less chance of development of microbial resistance. However, the fundamental question as to whether the antibacterial mechanism of GMs originates from parallel interaction or perpendicular interaction, or from a combination of these, remains poorly understood. Here, we show both experimentally and theoretically that GMs with high surface oxygen content (SOC) predominantly attach in parallel to the bacterial cell surface when in the suspension phase. The interaction mode shifts to perpendicular interaction when the SOC reaches a threshold of ∼0.3 (the atomic percent of O in the total atoms). Such distinct interaction modes are highly related to the rigidity of GMs. Graphene oxide (GO) with high SOC is very flexible and thus can wrap bacteria while reduced GO (rGO) with lower SOC has higher rigidity and tends to contact bacteria with their edges. Neither mode necessarily kills bacteria. Rather, bactericidal activity depends on the interaction of GMs with surrounding biomolecules. These findings suggest that variation of SOC of GMs is a key factor driving the interaction mode with bacteria, thus helping to understand the different possible physical mechanisms leading to their antibacterial activity.

Item Type: Article
Uncontrolled Keywords: graphene oxide, surface oxygen content, oxidative potential, membrane damage, antibacterial activity, interaction mode
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Life Courses and Medical Sciences
Depositing User: Symplectic Admin
Date Deposited: 02 May 2023 09:11
Last Modified: 29 Jun 2023 05:42
DOI: 10.1021/acsnano.2c10961
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